Mount Everest is the world's highest mountain, with a peak at 8,849 metres (29,031.7 ft) above sea level. It is situated in the Himalayan range of Solukhumbu district (Province 1 in present days), Nepal.
Timeline
1921: Reconnaissance expedition
The first British expedition—organized and financed by the newly formed Mount Everest Committee—came under the leadership of Colonel Charles Howard-Bury, with Harold Raeburn as mountaineering leader, and included George Mallory, Guy Bullock, and Edward Oliver Wheeler. It was primarily for mapping and reconnaissance to discover whether a route to the summit could be found from the north side. As the health of Raeburn broke down, Mallory assumed responsibility for most of the exploration to the north and east of the mountain. He wrote to his wife: "We are about to walk off the map..." After five months of arduous climbing around the base of the mountain, Wheeler explored the hidden East Rongbuk Glacier and its route to the base of the North Col. On September 23, Mallory, Bullock, and Wheeler reached the North Col at before being forced back by strong winds. To Mallory's experienced eye, the route up the North ridge intersecting the NE Ridge and from there to the summit looked long, but feasible for a fresher party.
1922: First attempt
The second British expedition, under General Charles Granville Bruce and climbing leader Lt-Col. Edward Lisle Strutt, and containing Mallory, returned for a full-scale attempt on the mountain. On May 22, they climbed to 8,170 m (26,800 ft) on the North Ridge before retreating. They were the first humans to climb above on a mountain. The scope of this accomplishment is reflected by the fact that there are only 14 mountains on earth—the eight-thousanders—that reach and exceed 8,000 metres. At that moment, Mallory and Strutt had exceeded the summit of all but five other mountains on the planet.
A day later, George Finch and Geoffrey Bruce climbed up the North Ridge and Face to 8,320 m (27,300 ft) using oxygen for the first time. They climbed from the North Col to their highest camp at a phenomenal rate of 900 vert-ft/hr., and were the first climbers to sleep using oxygen.
1924: Mallory and Irvine
The third British expedition was led by Brigadier-General Charles Bruce, although becoming indisposed as a result of a flare-up of malaria, he relinquished leadership of the expedition to Lt-Col. Edward Norton, with Mallory promoted to climbing leader. Geoffrey Bruce, Howard Somervell, and John Noel returned from the previous year, along with newcomers Noel Odell and Andrew Irvine.
On June 2, Mallory and Bruce set off from the North Col (C-4) to make the first summit attempt. But extreme wind and cold, exhaustion, and the refusal of the porters to carry farther led Mallory to abandon the attempt and the next day the party returned to the North Col camp.
On June 4, Norton and Somervell attempted an oxygenless summit in perfect weather; throat trouble forced Somervell to abandon the climb at about 28,000 feet (8534 m) while Norton continued on alone, reaching a height of 8,573 m (28,126 ft), just 275 m (900 ft) short of the summit. Exhausted, he turned back and rejoined Somervell for the descent.
On June 8, Mallory and Irvine left their high camp (C-6 at 26,900-ft) to attempt the summit, using Irvine's modified oxygen apparatus. Odell, climbing in support below, wrote in his diary that at 26,000-ft he "saw Mallory & Irvine on the ridge, nearing base of final pyramid" climbing what he thought at the time was the very difficult Second Step at 12:50 p.m. It was the last time the two were seen alive; whether either of them reached the summit remains a question that has reverberated through the decades.
Back in England, the climbing establishment pressured Odell to change his view. After about six months he began to equivocate on which Step it was he saw them—from the Second to possibly the First. If the First, they had no chance of having reached the top; if the Second, they would have had about three hours of oxygen each and the summit was at least three hours away. It is conceivable (though unlikely) that Mallory might have taken Irvine's remaining oxygen and attempted to reach the summit.